The University of Sheffield
Catchment Science Centre

Estimating urban loads of nitrogen to groundwater

D. N. Lerner

THE JOURNAL V17 N4 NOVEMBER 2003 239

Abstract

Urban areas can impose significant loads of nitrogen, as ammonium or nitrate, onto the underlying groundwater. There are many sources of nitrogen pollution, including diffuse sources (parks and gardens), intense point sources (industrial chemical spills), and multi-point sources (leaking sewers). Data on the loadings associated with the various sources are scarce, although an estimate of the overall load is available for Nottingham. For other cities, a total load could be estimated by factoring the Nottingham result, or by considering each component of the load separately. Both approaches are described, and the integrated method is recommended for its simplicity.

Key words

Contaminated land; groundwater; nitrate; Nottingham; sewers; urban.

Figure 1.Groundwater recharge and discharge under natural (left) and under urban (right) conditions.